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Clostridium thermocellum transcriptomic profiles after exposure to furfural or heat stress

BACKGROUND: The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing (CBP) biocatalyst for cellulosic ethanol production. It is capable of both cellulose solubilization and its fermentation to produce lignocellulosic ethanol. Intolerance to stresses routinely enco...

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Autores principales: Wilson, Charlotte M, Yang, Shihui, Rodriguez, Miguel, Ma, Qin, Johnson, Courtney M, Dice, Lezlee, Xu, Ying, Brown, Steven D
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3848806/
https://www.ncbi.nlm.nih.gov/pubmed/24028713
http://dx.doi.org/10.1186/1754-6834-6-131
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author Wilson, Charlotte M
Yang, Shihui
Rodriguez, Miguel
Ma, Qin
Johnson, Courtney M
Dice, Lezlee
Xu, Ying
Brown, Steven D
author_facet Wilson, Charlotte M
Yang, Shihui
Rodriguez, Miguel
Ma, Qin
Johnson, Courtney M
Dice, Lezlee
Xu, Ying
Brown, Steven D
author_sort Wilson, Charlotte M
collection PubMed
description BACKGROUND: The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing (CBP) biocatalyst for cellulosic ethanol production. It is capable of both cellulose solubilization and its fermentation to produce lignocellulosic ethanol. Intolerance to stresses routinely encountered during industrial fermentations may hinder the commercial development of this organism. A previous C. thermocellum ethanol stress study showed that the largest transcriptomic response was in genes and proteins related to nitrogen uptake and metabolism. RESULTS: In this study, C. thermocellum was grown to mid-exponential phase and treated with furfural or heat to a final concentration of 3 g.L(-1) or 68°C respectively to investigate general and specific physiological and regulatory stress responses. Samples were taken at 10, 30, 60 and 120 min post-shock, and from untreated control fermentations, for transcriptomic analyses and fermentation product determinations and compared to a published dataset from an ethanol stress study. Urea uptake genes were induced following furfural stress, but not to the same extent as ethanol stress and transcription from these genes was largely unaffected by heat stress. The largest transcriptomic response to furfural stress was genes for sulfate transporter subunits and enzymes in the sulfate assimilatory pathway, although these genes were also affected late in the heat and ethanol stress responses. Lactate production was higher in furfural treated culture, although the lactate dehydrogenase gene was not differentially expressed under this condition. Other redox related genes such as a copy of the rex gene, a bifunctional acetaldehyde-CoA/alcohol dehydrogenase and adjacent genes did show lower expression after furfural stress compared to the control, heat and ethanol fermentation profiles. Heat stress induced expression from chaperone related genes and overlap was observed with the responses to the other stresses. This study suggests the involvement of C. thermocellum genes with functions in oxidative stress protection, electron transfer, detoxification, sulfur and nitrogen acquisition, and DNA repair mechanisms in its stress responses and the use of different regulatory networks to coordinate and control adaptation. CONCLUSIONS: This study has identified C. thermocellum gene regulatory motifs and aspects of physiology and gene regulation for further study. The nexus between future systems biology studies and recently developed genetic tools for C. thermocellum offers the potential for more rapid strain development and for broader insights into this organism’s physiology and regulation.
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spelling pubmed-38488062013-12-06 Clostridium thermocellum transcriptomic profiles after exposure to furfural or heat stress Wilson, Charlotte M Yang, Shihui Rodriguez, Miguel Ma, Qin Johnson, Courtney M Dice, Lezlee Xu, Ying Brown, Steven D Biotechnol Biofuels Research BACKGROUND: The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing (CBP) biocatalyst for cellulosic ethanol production. It is capable of both cellulose solubilization and its fermentation to produce lignocellulosic ethanol. Intolerance to stresses routinely encountered during industrial fermentations may hinder the commercial development of this organism. A previous C. thermocellum ethanol stress study showed that the largest transcriptomic response was in genes and proteins related to nitrogen uptake and metabolism. RESULTS: In this study, C. thermocellum was grown to mid-exponential phase and treated with furfural or heat to a final concentration of 3 g.L(-1) or 68°C respectively to investigate general and specific physiological and regulatory stress responses. Samples were taken at 10, 30, 60 and 120 min post-shock, and from untreated control fermentations, for transcriptomic analyses and fermentation product determinations and compared to a published dataset from an ethanol stress study. Urea uptake genes were induced following furfural stress, but not to the same extent as ethanol stress and transcription from these genes was largely unaffected by heat stress. The largest transcriptomic response to furfural stress was genes for sulfate transporter subunits and enzymes in the sulfate assimilatory pathway, although these genes were also affected late in the heat and ethanol stress responses. Lactate production was higher in furfural treated culture, although the lactate dehydrogenase gene was not differentially expressed under this condition. Other redox related genes such as a copy of the rex gene, a bifunctional acetaldehyde-CoA/alcohol dehydrogenase and adjacent genes did show lower expression after furfural stress compared to the control, heat and ethanol fermentation profiles. Heat stress induced expression from chaperone related genes and overlap was observed with the responses to the other stresses. This study suggests the involvement of C. thermocellum genes with functions in oxidative stress protection, electron transfer, detoxification, sulfur and nitrogen acquisition, and DNA repair mechanisms in its stress responses and the use of different regulatory networks to coordinate and control adaptation. CONCLUSIONS: This study has identified C. thermocellum gene regulatory motifs and aspects of physiology and gene regulation for further study. The nexus between future systems biology studies and recently developed genetic tools for C. thermocellum offers the potential for more rapid strain development and for broader insights into this organism’s physiology and regulation. BioMed Central 2013-09-12 /pmc/articles/PMC3848806/ /pubmed/24028713 http://dx.doi.org/10.1186/1754-6834-6-131 Text en Copyright © 2013 Wilson et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Wilson, Charlotte M
Yang, Shihui
Rodriguez, Miguel
Ma, Qin
Johnson, Courtney M
Dice, Lezlee
Xu, Ying
Brown, Steven D
Clostridium thermocellum transcriptomic profiles after exposure to furfural or heat stress
title Clostridium thermocellum transcriptomic profiles after exposure to furfural or heat stress
title_full Clostridium thermocellum transcriptomic profiles after exposure to furfural or heat stress
title_fullStr Clostridium thermocellum transcriptomic profiles after exposure to furfural or heat stress
title_full_unstemmed Clostridium thermocellum transcriptomic profiles after exposure to furfural or heat stress
title_short Clostridium thermocellum transcriptomic profiles after exposure to furfural or heat stress
title_sort clostridium thermocellum transcriptomic profiles after exposure to furfural or heat stress
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3848806/
https://www.ncbi.nlm.nih.gov/pubmed/24028713
http://dx.doi.org/10.1186/1754-6834-6-131
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